The word "unliquefied" refers to a substance that has not been melted or turned into a liquid. Synonyms for this word include "solid," "unchanged," "unmelted," and "undissolved." Other related words that could describe the state of a substance that has not been turned into a liquid include "unmolten," "unmelted," "frozen," "unthawed," "hard," and "stiff." The opposite of "unliquefied" would be "liquefied" or "molten," both of which indicate a substance that has been turned into a liquid through the application of heat or another method of melting.